Rotary casting



March 10, 1931.

F. G. CARRINGTON ROTARY CASTING Filed July 6, 1927 Patented Mar. 10, 1931 UNITED. STATES PATENT OFFICE FRANK s. cannmsron, on ANNISTON, ALABAMA, assmnon r r-nnnrc ENGINEER- ING- COMPANY, or ANNISTON, ALABAMA, A. conrona'rron or DELAWARE ROTARY Application filed July 6,

This invention relates to a centrifugal casting apparatus and has more particularly to' 1 Should the pipe not be provided with a bell,

a plain end core or ring may be inserted in the mold. Other types of pipe require varying shapes and forms of cores in the casting operation. All these cores above referred to must be held securely in the core seat of the mold, and it is to the fastening of the core while the mold is rotatin that this invention particularly refers. Gther applications for patents of this applicant (namely,

application Serial No. 203,832, filed July 6,

1927 5 application Serial No. 203,833, hled July 6, 1927; and application Serial No. 204,566, filed July 9, 1927) .are directed to the insertion and removal of the core and pipe while the mold is rotating.

It is to be understood that the term core as used throughout this specification and claims refers to all devices which preventv escape of molten metal from a'nend of the so mold, and which are adapted to be detach able after each casting operation.

The apparatus heretofore employed for fastening a core in a mold have necessitated the stopping of the molds rotation both at at the time of fastening and untastening the core. it is desirable that the mold never cease rotating, for circumferentially it is subjected to a non-uniform cooling when stationary, and difierences in temperature are an especially to be avoided in the centrifu al casting of pipe. Usually the bottom 0 a mold is cooled at a greater rate than the top,

which if the mold is permitted to remain stationary, results in a warpage of the mold and also the pipe contained therein.

In addition to the warpage of the mold andpipe there is also an uneven cooling of the pipe if rotation is stopped, which causes a variance in its structure. When the pipe cools, there is an attendant shrinkage of it,

casrme 1927. Serial no. 203,835.

which results in its resting on the bottom of the mold. If the mold remains stationary there then results one line axially of the mold and pipe which is subjected to a greater heat exchange than the rest of the pipe, resulting in a non-uniform cooling. By permitting the mold to continue to rotate the circumferences of themold and pipe are uniformly cooled.

The devices heretofore used in fastening a core in a mold have also failed to provide means for insuring a tight fit when parts of the apparatus are worn. When there has been a shrinkage or wearing of the apparatus, there has usually resulted a leakage of the molten metal from the mold and the formation of fins on the cast pipe. Inasmuch as the fins are of slight cross section they are subjected to a more rapid cooling than the body of the pipe, causing shrinkage cracks which often extend into the body of the pipe.

Aside from the harm done to the ipe and apparatus by the devices hereto ore employed, there has also resulted a needless loss of time which can be averted by my invention. Inasmuch as a complete casting cycle is of a duration of little more than a minute, the necessity for stopping and start- .ing the rotation of a mold twice during a casting operation increases the time consumption appreciably.

- To overcome the difficulties inherent in the apparatus heretofore used is one of the objects of this invention.

Another object is to provide an apparatus for fixedly maintaining a core in a mold.

A further object of this invention is to provide an apparatus for fixedly maintaining a core in a mold capable of adjustment while the mold is rotating.

A. still further object of this invention is to provide an apparatus for positioning a core in a mold while the latter is rotating.

To accomplish the above objects, and others, as will more fully hereinafter appear, my invention comprises in general means for securely holding a core in a mold and other means for actuating the first mentioneda means while the mold is either stationary or rotating.

Iniorder to insure a complete comprehen- Fig. 2 is a cross sectional view of the apparatus shown in F i 1 along the line 22 of Fi 1, looking in t 1e direction of the arrows;

ig. 3 is a View, partly in section and artly in elevation, along the line 3-3 of ig. 1 looking in the direction of the arrows.

Referring more particularly to Fig. 1, there is shown an end plate 1 of a casting apparatus which is suitably mounted by means of bolts 2 on brackets or support members (not shown in the drawing) for the complete apparatus. There is also shown a core 3 comprising a metal casing 4 and a compressed sand body portion 5, as is more clearly shown in F 2. While 1 have shown my invention in conjunction with a bell core, it is to be understood that it is adapted for use with a plain end pipe core. A frusto-conical opening 6 is provided in the center of the sand body, adapted to receive an apparatus for extracting the core from the mold. The outside of the metal casing is beveled as at 7 to fit a corresponding beveled portion of the mold. A shoulder 8 is provided in the mold to limit the extent to which the core may be inserted. A. shouldered portion 9 of the sand body projects inwardly and is provided with an annuar protuberance 11 for forming the lead ring of a pipe.

Referring again to Fig. 1, there are mount- 7 ed near the outer face of the bell end of a mold 12 dogs 13 spaced about the mold. Recesses 14 are formed in the mold adapted to receive pivot arms 15 of the dogs and permit .partial rotation of the pivot arms. Bolts 16, or other suitable ivoting means, extend through the mold an pivot arms 15.

The dogs are rovided with two arms. One arm 17 is angu arly disposed to the perpendicular of the pivot arm 15. Another arm 18 is substantially perpendicular to the pivot arm.

The arm 18 is provided with a projection 19 which extends through a slot 21 in the mold and projects over the outer end of the metal casing 4 when the core is in position. Referring to Fig. 2, it will be observed that the inner side of the projection 19 is of wedge formation as at 22. As the wedged surface 22 traverses the face of the metal casing 4, therefore, the core is forced further into the bell cavity. The extent of such insertion is limited by the shoulder 8 which prevents any movement of the casing beyond that point.

Over a series of casting operations, the apparatus is subjected to considerable wear, and this is particularly true with respect to the arms 19, core casing 4 and the shoulder 8. When such wear occurs it may be compensated for by further projecting the arm 29 across the casing 4. This insures a tight fit between the casing and the mold, and prevents the leakage of any molten metal from the mold. I

Referring to Fig. 3, a top view of the dogs is shown. t will be noted that the arms 17 and 18 do not lie in the same plane, the reason therefor appearing hereinafter. The inner side of the arm 17 lies in the same plane as the outer side of the arm 18.

While I have shown in detail particular means for maintaining the core in a fixed position in the mold, and while I have referred to such means as dogs both in. the de scription and appended claims, various other structures may be employed to accomplish the desired results sought and obtained by the means herein shown. It is to be understood that substitution of such equivalent structure will not fall without the scope of the appended claims.

Referring again to Fig. 1, there is shown mounted on the plate 1, levers 23 and These lovers are composed of handles and 25 respectively angularly disposed to arms 26 which are pivoted at 27 Angularly disposed to the arms 26 are arms 28 and 28. Movement of the arms 23 and 24 throws the arms 28 and 28 respectively into position n where they contact with the dogs, as is shown by the lever 24, indicated by dotted lines. The dogs rotate with the mold, and when the levers 23 and 24- are in operative position the dogs successively come into contact with the arms 28, 28.

Referring to Fig. '3, the arm 24 isse arated from the plate 1 by means of a was er 29, and is separated from the arm 23 by a washer 31. Another washer 32 is interposed between the arm 23 and a bolt. The bolt is kept sufficiently tight to prevent any free movement of the levers 23 and 24, but does permit their rotation when desired. The

lever 24, through arm 28, contacts with the arm 18 of the dogs when in operative position. This forces the projection 19 through the aperture 21 and across the face of the casing 4 of the core.

The extent to which arms 18 and 19 move in a clockwise direction about the pivot 16 determines the distance to which the core casing 4 is forced in the mold. The projection 19 is forced across the casing 4 until the shoulder 8 and the inner end of casing 4 contact. The core is thus held securely in the bell seat of the mold.

The arm 28 of the lever 23 contacts with the arm 17 of the dogs. When the lever 23 is in operative position, the arms 17 of the successive dogs are forced against the arm 28. This depresses the arm 17 and frees the projection 19 from engagement with the core casing 4. Then all of the arms 19 are thus free the core may be removed from or starting the mol has been appreciab e.

inserted in the mold. The handles 25 and 25 of the levers 23 and 24 respectively are arms 17 of the dogs mounted on the rotating mold are forced against the mold and the projections 19 then aflord no obstruction. to injection of a core. While the mold is rotating the core is inserted within the bell cavity. It is not necessary that the core be put in its exact final position, but only that the face of the metal casing 4 permits a partial contact with the surfaces 22 of the projections 19.

After the core is placed in the mold, the lever 23 is thrown into inoperative position and the lever 24 is then thrown into operative position as indicated by the dotted lines in Fig. 1, and forces the arms 18 in a clockwise movement. This throws projection 19 across the face of casing 41 Should the core be inserted in the bell so that the shoulder 8 does not contact with the inner end of the casing 4;, the wedged arms 19 force the casing inwardly. The extent of this movement of he arms 19 is determined by the position of the arm 28 and the shoulder 8.

After the core is securely placed in the mold the pouring operation commences. When pouring has ceased and the casting sufficiently cooled for removal, with or without a diminution in the speed of the mold, the core may be removed. The lever 24 is moved so that it does not contact with the arms 18 when the mold is rotated, and the lever 23 is then thrown into operative position forcing the arms 17 of the dogs against the outer circumference of the mold. With the withdrawal of the projections 19 from the face of the core casing 4, the core may be removed, and suitable extracting apparatus may be employed to withdraw the core and pipefrom the mold.

It will thus be seen that my invention allows an operator to fasten or unfasten a core in a mold while rotating. As abovepointed out, this insures a uniform coolin which in turn prevents warpage of the mol and pipe heretofore resulting from uineven cooling. With an even heat exchange between all points on the circumference of the pipe and the mold, the variance in the structure of the pipe caused by a non-uniform cooling is also prevented.

The time-saving features ofmy invention are apparent, when it is remembered that a complete pipe may be cast and removed in about a mmute. The percentage of this time heretofore lost b reason ofstoppin an;

saving in labor is also efi'ected for one man may operate my device, even at the same time that he is engaged in other phases of the casting operation.

I have shown in the accompanying drawings, and have described in this application with some detail a device that would accomplish the beneficial results sought, not for the purpose of limitation but to insure a clear comprehension of my invention. It is, of course, obvious that many modifications may be made in the structure and method of operation of the herein described apparatus, and it is to be understood that the invention is limited merely by the'scope of the appended claims.

' I claim:

; 1. A centrifugal casting apparatus comprising a mold and a core, means on the mold for adjusting the position of the core in the mold while the mold is rotating.

2. In a centrifugal casting apparatus, a mold, a core holding device comprising a dog mounted on the mold, said dog having a core engaging portion, an arm angularly disposed on the dog, a non-revolving member, and means mounted on said non-revolving member for contactin with the arm.

3. In a centri ugal casting apparatus, a mold, a core holding device comprising dogs mounted on the mold, said dogs having core engaging portions, actuating arms for the dogs, a stationary member adjacent the mold, and a lever mounted on said stationary member for contactin with the arms.

I 4. In a centri gal casting apparatus, a mold, a core holding device comprising a dog mountedon the mold, actuating arms carried by the dog, a wedge surface on one arm adapted to contact with the outer end of the core, a stationary member adjacent the mold,

and levers pivotally mounted on said stationary member adapted to contact with the dog arms.

5. In a' centrifugal casting apparatus, a device for securing a core in a rotating mold, comprislng pivoted wedges mounted on one end of the mold, a lever mounted stationary with respect to the mold and adapted to con tact with the wed es to cause engagement of the wedges with t e core and another lever adapted to contact with the wedges to disengage them from'the core.

6. A centrifugal casting apparatus comprising a mold having a ortion adapted to receive a core, a core-ho ding device asso ciated with the mold comprising a dog mounted on the mold, said do having a plurality of armilike portions an a core engaging ortion, and means mounted on a nonrevo ving portion of the casting apparatus engageable with the arm like portions of the dog to actuate the dog while the mold is retilting;1

7. a centrifugal casting apparatus has;-

4 meats? in a mold, a core-holding device comprising a 0g having a core engaging portion pivoted on the rotatable mold, actuating arms for the dog, a lever mounted on a non-rotating 5 member for contacting with one of the arms of the dog, and a second lever on said member for contactin with the other arm of the dog, said levers ing operable for moving the dog into and out of engagement with the 10 core.

8. A centrifugal casting apparatus comprising a mold having a core receiving portion, a plurality of ogs circumferentially spaced about the core receiving ortion of m t e mold, said dogs oonsistin o a pan of arms ofl'set relative to each 0t er, a. core eng 'ng element carried by one of said arms an s a pair of levers mounted on a stationary ortion of the casing apparatus, one of said so evers adapted to engage one arm of each dog to fasten the core in the mold, and the other of said levers adapted to engage the other arm of each dog to unfasten the core from the mold.

35 9. A centrifugal casting apparatus comprising a mold having a core receiving p0rtion, a plurality of dogs circumferentially s aced about the core receiving portion of t e mold, each of said dogs consisting of a lug pivotally mounted on the mold, an actuating arm carried by said lug, a second actuating arm carried by said lug and oflset relative to the first arm, a core engaging element carried by one of said arms and extending through an aperture in the mold, and means carried by a non-rotating portion of the a aratus for engaging the arms to actuate t e I fn testimon whereof I afix my signature.

A o F ANK G". CARRINGTON. 

